With an increase in a quantity of users in a mobile communications system, and in particular, an increase in a traffic volume number of a single user, wireless resources are increasingly becoming scarce resources.
In an FDD (frequency division duplex) system, a same bandwidth is used for an uplink frequency band and a downlink frequency band. However, currently, an uplink traffic volume is far less than a downlink traffic volume, which means that relatively more wireless spectrum resources need to be allocated, to meet a requirement of the downlink traffic volume. It is learned from a use process that when these wireless spectrum resources are used for transmitting an uplink service, a large quantity of wireless spectrum resources are idle, and this problem causes relatively low utilization of the wireless spectrum resources.